Connector means for connecting coaxial cable to a printed circuit board



May 14, 1968 w. M C ER ET AL 3,383,457

CONNECTOR MEANS FOR CONNECTING COAXIAL CABLE TO A PRINTED CIRCUIT BOARD Filed April 5, 1966 2 Sheets-Sheet 1 y 14, 1968 w. 1.. SCHUMACHER ET AL 3,383,457

CONNECTOR MEAN TO 5 FOR CO CT COAXIAL CABLE A PRINTED CU BOARD Filed April 5, 1966 2 Sheets-Sheet 2 United States Patent Office 3,383,457 Patented May 14, 1968 3,383,457 CONNECTOR MEANS FOR CONNECTING COAXIAL CABLE TO A PRINTED CIRCUIT BOARD William Ludlow Schumacher, Camp Hill, and John Henry Huber, Harrisburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Apr. 5, 1966, Ser. No. 540,410 Claims. (Cl. 174-68.5)

ABSTRACT OF THE DISCLOSURE A structure for terminating conductive members of a coaxial cable on .a dielectric supporting member comprises U-shaped ferrule members, means for securing the ferrule members on the dielectric supporting member in spaced relationship for receiving therein respective conductive members of the coaxial cable, the ferrule members being crimpable onto the respective conductive members with the dielectric supporting member being part of an anvil during the crimping operation. Ferrule elements are disposable on the inner insulation of the coaxial cable and in engagement with the respective conductive members to assure minimum disturbance to the insulation when the ferrule members are crimped onto the ferrule elements.

This invention relates to connector means and more particularly to a connector means for connecting coaxial cable to a printed circuit board or the like.

The use of coaxial or multiconductor cable on a supporting member, such as a printed circuit board, is becoming prevalent because of at least two circuits contained in a single structure. A major problem in applying a coaxial cable to a printed circuit board is the termination of the conductive members thereof.

A primary object of the invention is the termination of conductive members of a coaxial cable to a printed circuit board.

Another object of the invention is the provision of a terminating means for conductive members of a coaxial cable that saves time and handling expense.

A further object of the invention is to provide a connector means on a dielectric supporting member which provides dielectric spacing between members of the connector means to terminate conductive members of a co axial cable.

An additional object of the invention is the provision of a connector means securable on a printed circuit board which uses the printed circuit board as an anvil to crimp the conductive members of a coaxial cable within the spaced members of the connector means.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

The foregoing objects are achieved by a structure for terminating conductive members of a coaxial cable on a dielectric supporting member comprising U-shaped ferrule members, means for securing said ferrule members on the dielectric supporting member spaced from one another for receiving therein respective conductive members of the coaxial cable, the ferrule members being crimpable onto the respective conductive members with the dielectric supporting member being part of an anvil during the crimping operation. Ferrule elements are disposable on the inner insulation of the coaxial cable and in engagement with the respective conductive members.

In the drawings:

FIGURE 1 is an exploded perspective view of connector means on a dielectric supporting member and a coaxial cable;

FIGURE 2 is a view similar to FIGURE 1 with the conductive members of the coaxial cable crimped in the members of the connector means;

FIGURE 3 is a view taken along lines 3-3 of FIG- URE 2;

FIGURES 4 and 5 illustrate cross-sectional action views of the crimping operation with FIGURE 5 being taken along lines 5-5 of FIGURE 3; and

FIGURE 6 is a cross-sectional view of the crimped connection taken along lines 66 of FIGURE 3.

Turning now to the drawings and particularly FIG- URES 1 through 3, there is shown a supporting member SM of dielectric material which is, for example, a printed circuit board or the like. For the purposes of describing the invention, supporting member SM will be a printed circuit board having conductive paths 1 disposed thereon. Holes 2 extend through the printed circuit board at spaced locations and through the conductive paths.

U-shaped ferrule members 3 and 4 have securing l-ugs 5 extending outwardly from each end of the bight of the ferrule members and the securing lugs extend in a direction opposite to that of the legs of the ferrule members. Securing lugs 5 are disposed in respective holes 2 in supporting member SM so that the securing lugs 5 of ferrule member 3 will be electrically connected to the conductive path for this ferrule member and the securing lugs of ferrule member 4 will be connectable to the conductive path for this ferrule member. Securing lugs 5 are connected to their respective conductive paths by welding, soldering, clinching or in any other suitable manner. The bight of ferrule member 4 extends beyond the legs of this ferrule member and offset insulationengaging lugs 6 extend outwardly from this bight and each insulation-engaging lug extends in a direction parallel inside surfaces of the legs of ferrule member 4 may have spaced grooves 7 disposed therein to define serrated surfaces. These serrated surfaces provide good, electrical contact as well as additional tensile grip on the conductors to be engaged. If desired, the inside surfaces of the legs of ferrule member 3 may also be serrated as well as the inside surfaces of the bights of each ferrule member.

Coaxial cable 8 comprises an outer insulation sheath 9, braided outer conductor 10, an inner insulation sheath 11 and an inner stranded conductor 12. Annular ferrule members 13 of hard metal are disposed on inner insulation sheath 11 with one of the ferrule members being disposed under outer conductor 10 and stranded conductor 12 is bent back across the other ferrule member as illustrated in FIGURE 1. The outer end of the ferrule member onto which stranded conductor 12 is bent back over in spiral fashion has an annular flange 14 to abut against the end of insulation sheath 11 to position this ferrule member at this location.

After coaxial cable 8 has been properly stripped and ferrule members 13 properly positioned on insulation sheath 11, ferrule members 13 and respective outer conductor 10 and inner conductor 12 along therewith are positioned within respective ferrule members 3 and 4. Supporting member SM is then placed on an anvil with ferrule members 3 and 4 being positioned thereover as illustrated in FIGURES 4 and 5. Crimping die 16 having a U-shaped configuration is then brought into engagement with ferrule members 3 and 4 and insulationengaging lugs 6, and, during downward movement of crimping die 16, the legs of ferrule members 3 and 4 and lugs 6 are bent into engagement with respective ferrule members 13 and outer conductor 1% and center conductor 12 in engagement with ferrule members 13; insulation engaging lugs 6 are bent into engagement with outer insulation sheath 9 to form a strain relief for the connection. This provides a termination of the conductive members of a coaxial cable to conductive paths of a printed circuit board having excellent electrical characteristics. This termination is such as to minimize disturbance of the characteristic impedance of the coaxial cable. As can be discerned, ferrule members 13 provide back-up pressure during the crimping of ferrule members 3 and 4 thereonto and supporting member SM is disposed between ferrule members 3 and 4 and anvil 15 during the crimping operation. Crimping die 16 may be a unitary die or the die may have separate dies mounted on a die block for ferrule members 3 and 4 and lugs 6. The ferrule members are preferably made of substantially soft metal so as to be readily crimped onto the conductive members without any damage to the printed circuit board. Ferrule members 13, as mentioned hereinbefore, are of sufficiently hard metal in order to provide back-up means during the crimping operation and these ferrule members resist any significant deformation so as not to impart any substantial discontinuity to the inner insulation. As can be discerned from FIGURE 6, spiralling of inner conductor 12 around ferrule member 13 results in this inner conductor to be effectively crimped; otherwise, if the inner conductor was not spirally disposed on ferrule member 13, it could rest in the corner spaces without providing a proper termination. Of course, lugs 6 are also not crimped too tightly onto insulation 9 so as to provide no discontinuity thereat.

It is preferable to secure ferrule members 3 and 4 as well as other electrical components onto the printed circuit board and then crimp the coaxial cable to the ferrule members. This saves time and handling expense which are essential features. The printed circuit board or supporting member serves as a dielectric spacer member to insulate ferrule member 3 from ferrule member 4 thereby eliminating any supporting member therebetween. Center conductor 12 may be very fine stranded material or solid material. If the coaxial cable is a semi-rigid coaxial cable with the outer conductor being made of tubular metal, rear ferrule member 13 may be eliminated and lugs 6 may be used, if desired. The termination of coaxial cable in the foregoing manner is susceptible to high speed terminating techniques which is receptive to automation capabilities to provide terminations of excellent electrical characteristics. Coaxial cable having more than two conductive members may be terminated in accordance with the foregoing provisions.

As can be discerned, there has been disclosed a unique and novel connector means securable on a supporting member for connecting conductive members of a coaxial cable means to the supporting member.

It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiment of the invention, which is shown and described herein, is intended as merely illustrative and not as restrictive of the invention.

The invention is claimed in accordance with the following:

1. As an article of manufacture, a connection assembly for terminating coaxial cable having a center conductor surrounded by insulation and an outer annular conductor, said connection assembly comprising a first U-shaped ferrule member and a second U-shaped ferrule member, means for securing said ferrule members on a dielectric supporting member in electrical engagement with respective conductive paths thereon and in spaced insulated relationship, annular ferrule members disposable on said insulation in spaced relationship with one ferrule member underneath said outer annular conductor and the other ferrule member adjacent an end of said insulation with said center conductor being bent back over and along this other ferrule member, said annular ferrule members being disposable within respective U-shaped ferrule members along with said outer conductor and center conductor and said U-shaped ferrule members being crimpable into electrical engagement with said annular ferrule members and said conductors thereon with said annular ferrule members being of sufficiently hard material to assure a minimum disturbance to said insulation.

2. A connection assembly according to claim 1 wherein one of said U-shaped ferrule members includes insuladon-engaging lugs crimpable onto an outer insulation sheath on said coaxial cable.

3. A connection assembly according to claim 1 wherein said U-shaped ferrule members include inner serrated surfaces.

4. A connection device terminating a coaxial cable including a center conductor surrounded by insulation and an outer conductor, said connection device comprising in combination a dielectric supporting member having conductive paths thereon, U-shaped ferrule members including means securing said ferrule members on said dielectric supporting member in spaced and insulated relationship and in electrical engagement with respective conductive paths, ferrule means on said insulation adjacent said center conductor with said center conductor bent over and along said ferrule means, said outer conductor and said ferrule means with said center conductor in engagement therewith being disposed in respective ferrule members and said ferrule members being crimped into electrical engagement with said outer conductor and said ferrule means and center conductor.

5. A connection device according to claim 4 wherein said center conductor is spirally wound around said annular ferrule member.

6. A connection device according to claim 4 wherein additional ferrule means is disposed on said insulation under said outer conductor.

7. A connection device according to claim 4 wherein said coaxial cable includes an outer insulation sheath and one of said ferrule members includes insulation-engaging lugs crimped onto said outer insulation sheath of said coaxial cable.

8. In an electrical connection between conductors of a coaxial cable and a connection device; said coaxial cable comprising a center conductor, an outer conductor and insulation therebetween; said connection device comprising a dielectric supporting member having conductive paths, ferrule members secured on said dielectric supporting member in electrical engagement with respective conductive paths and insulatively spaced from each other; ferrule means on said insulation and spaced from each other, one of said ferrule means being disposed under said outer conductor and this ferrule means and outer conductor being secured within one of said ferrule mem- 10. The electrical connection according to claim 8 bers, another of said ferrule means being disposed adjawherein said coaxial cable includes an outer insulation cent said center conductor With said center conductor beh th d one f id f rul me ber includes insulaing disposed along said other ferrule means and the other tion-engaging lugs secured on said outer insulation sheath ferrule means and center conductor thereagainst being se- 5 cured Within the other of said ferrule members.

9. The electrical connection according to claim 8 where- No references cited in said ferrule means are of material substantially harder than said ferrule members. DARREL L. CLAY, Primary Examiner.

of said coaxial cable. 

